We report a new method for fabrication of research-grade glass microfluidic devices using a household microwave oven. The transformative step in this technique is the formation of the microchannel and fusion bonding of the glass layers in a single step. This is demonstrated here using a non-photolithographic technique for both high aspect ratio rectangular and circular cross-section microchannels. In this paper, the microfluidic devices are fabricated utilizing a thin paper cutout as the sacrificial channel layer, glass blanks, and a microwave kiln sold commercially for arts and crafts. Glass microfluidic devices are fabricated in a microwave oven in as short as 2 min.